IP Law Daily, PATENT—Fed. Cir.: PTAB’s anticipation finding reversed in wireless communication system dispute, (Mar 10, 2025)

By Kevin M. Finson, J.D.

Patent claims for checking errors in wireless communications were not anticipated by a prior art reference because the patent required that two limitations be met together, not in the alternative, in order to fall within the claimed method, while the prior art reference had only covered one of the two.

A group of sellers of wireless communications equipment failed to show that a Sisvel SPA patent they challenged was anticipated by prior art, the U.S. Court of Appeals for the Federal Circuit has held. The Patent Trial and Appeal Boad had erroneously required that two claim limitations be met in the alternative when the claim language required that both be met (Sierra Wireless, ULC, v. Sisvel, SPA, Nos. 23-1059, 23-1085, 23-1089, 23-1125, (Fed. Cir. March 10, 2025)).

Sisvel, SPA (Sisvel) was the owner of U.S. Patent No. 7,869,396 (the ’396 patent), which related to “a data transmission method and a data retransmission method which can reduce loss in data transmission” in a wireless communication system; specifically, an improved variation on a prior art technique known as Automatic Repeat Request (ARQ). Sierra Wireless, ULC and several other companies (collectively, Sierra) petitioned for inter partes review of all claims on the ground of anticipation and obviousness over a certain International Patent Application. The Patent Trial and Appeal Board (PTAB) instituted review and found claims 1, 2, and 6-8 unpatentable, and that claims 3-5, 9, and 10 had not been shown to be unpatentable. Both parties appealed.

Cross-appeal. The Federal Circuit began with Sisvel’s cross-appeal challenging the finding that claims 1, 2, and 6-8 were unpatentable as anticipated. The court found that the Board had erred in finding two limitations were mutually exclusive, and therefore finding that the claims were anticipated when the prior art reference disclosed one but not the other. The plain language of the claims showed that the claimed method required both limitations be performed when stated preconditions were met.

Appeal. The Federal Circuit noted that because it was reversing the Board’s findings on the independent claims in the cross appeal there was no need for it to consider the decisions on the dependent claims which had been raised by Sierra’s direct appeal. However, the court took the opportunity to explain that the Board had abused its discretion by crediting the testimony of Sisvel’s declarant as a person of ordinary skill in the art when he lacked the educational credentials the Board had previously found would be required of a person of ordinary skill. The expert undoubtedly possessed many years of experience in the field, but the Board had failed to make an explicit finding that his experience was equivalent to the education credentials.

The court reversed and remanded the case for further proceedings.

The case is Nos. 23-1059, 23-1085, 23-1089, 23-1125.

Judge: Moore, K.

Attorneys: Kourtney Mueller Merrill (Perkins Coie LLP) for Sierra Wireless, ULC. Robert J. Gajarsa (Devlin Law Firm LLC) for Sisvel S.p.A.

Companies: Sierra Wireless, ULC; Sisvel S.p.A

Cases: Patent FedCirNews USPTO